/* ═══════════════════════════════════════════════════════
   LearnSpace — Shared Design System  /css/ls.css
   ═══════════════════════════════════════════════════════ */

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Design tokens ── */
:root {
  --bg:       #EEF2FF;
  --surface:  rgba(255,255,255,0.82);
  --border:   rgba(15,23,42,0.10);
  --border-h: rgba(15,23,42,0.20);
  --text:     #0F172A;
  --text-2:   #3D4F6B;
  --text-3:   #56687A;   /* WCAG AA: ~5.1:1 on white, ~4.6:1 on --bg */

  --violet: #9B5DE5;
  --cyan:   #06D6E0;
  --green:  #06D664;
  --pink:   #F15BB5;
  --amber:  #FFB347;

  --grad-1: linear-gradient(135deg, #06D6E0, #9B5DE5);

  /* Spacing scale (4px base) */
  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-5:  20px;
  --space-6:  24px;
  --space-8:  32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;

  /* Radius ladder */
  --r-xs:  4px;
  --r-sm:  8px;
  --r-md:  12px;
  --r-lg:  20px;
  --r-xl:  24px;
  --r-pill: 999px;

  /* Semantic color aliases */
  --success: var(--green);
  --warning: var(--amber);
  --danger:  var(--pink);
  --info:    var(--cyan);

  /* Typography scale */
  --text-xs:   0.72rem;
  --text-sm:   0.82rem;
  --text-base: 0.92rem;
  --text-md:   1.02rem;
  --text-lg:   1.18rem;
  --text-xl:   1.5rem;
  --text-2xl:  2rem;
  --text-3xl:  2.6rem;

  /* Font-weight scale */
  --fw-regular:   400;
  --fw-medium:    500;
  --fw-semibold:  600;
  --fw-bold:      700;
  --fw-extrabold: 800;

  /* Motion */
  --ease-out:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 0.12s;
  --duration-base: 0.22s;
  --duration-slow: 0.40s;

  /* Layout breakpoints (documentation only — CSS @media doesn't support var()) */
  --bp-mobile:  640px;
  --bp-tablet:  1024px;
  --bp-desktop: 1280px;

  --blur:   blur(20px);
  /* two-layer shadow: crisp + ambient */
  --shadow:   0 2px 8px rgba(15,23,42,0.08), 0 8px 40px rgba(15,23,42,0.10);
  --shadow-h: 0 4px 16px rgba(15,23,42,0.12), 0 16px 56px rgba(15,23,42,0.13);

  --tr: 0.22s ease;
}

/* ── Body + dot-grid ── */
body {
  font-family: 'Manrope', sans-serif;
  background: var(--bg);
  background-image: radial-gradient(circle, rgba(15,23,42,0.055) 1px, transparent 1px);
  background-size: 22px 22px;
  min-height: 100vh;
  color: var(--text);
}

/* ── Custom scrollbar ── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(155,93,229,0.35); border-radius: 99px; }
::-webkit-scrollbar-thumb:hover { background: rgba(155,93,229,0.60); }

/* ── Focus ring ── */
:focus-visible { outline: 2px solid var(--violet); outline-offset: 3px; }

/* ── Icon-only button (WCAG 2.5.5: 44×44 tap area) ── */
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 44px; min-height: 44px;
  border: none; border-radius: 10px;
  background: transparent;
  cursor: pointer;
  transition: background var(--tr), color var(--tr);
  color: var(--text-2);
  flex-shrink: 0;
}
.icon-btn:hover { background: rgba(155,93,229,0.08); color: var(--violet); }
.icon-btn svg { width: 20px; height: 20px; }

/* ── Navbar ── */
.nav {
  position: sticky; top: 0; z-index: 100;
  padding: 10px 24px;
  display: flex; align-items: center; justify-content: space-between;
  background: rgba(238,242,255,0.90);
  backdrop-filter: var(--blur);
  border-bottom: 1px solid var(--border);
}
.nav-logo {
  font-family: 'Unbounded', sans-serif;
  font-size: 1rem; font-weight: 800;
  color: var(--text); text-decoration: none;
  letter-spacing: -0.01em;
}
.nav-logo span {
  background: var(--grad-1);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav-right { display: flex; align-items: center; gap: 10px; }

/* nav user avatar chip */
.nav-user-chip {
  display: flex; align-items: center; gap: 8px;
  padding: 4px 12px 4px 4px;
  background: rgba(155,93,229,0.07);
  border: 1.5px solid rgba(155,93,229,0.18);
  border-radius: var(--r-pill);
}
.nav-avatar {
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--grad-1);
  display: flex; align-items: center; justify-content: center;
  font-family: 'Unbounded', sans-serif;
  font-size: 0.62rem; font-weight: 800; color: #fff;
  flex-shrink: 0;
}
.nav-user-name {
  font-size: 0.78rem; font-weight: 600; color: var(--text-2);
  max-width: 140px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}

/* legacy .nav-user (plain text) */
.nav-user { font-size: 0.85rem; color: var(--text-2); }

.btn-nav {
  padding: 6px 16px;
  border: 1.5px solid var(--border-h);
  border-radius: var(--r-pill);
  background: transparent;
  font-family: 'Manrope', sans-serif; font-size: 0.8rem; font-weight: 600;
  color: var(--text-3);
  cursor: pointer; text-decoration: none; display: inline-block;
  transition: all var(--tr);
}
.btn-nav:hover { border-color: var(--violet); color: var(--violet); }
.nav-active {
  background: rgba(155,93,229,0.08) !important;
  border-color: var(--violet) !important;
  color: var(--violet) !important;
  cursor: default; pointer-events: none;
}

/* ── Shimmer btn-primary ── */
.btn-primary {
  position: relative; overflow: hidden;
  padding: 10px 26px;
  min-height: 44px;   /* WCAG 2.5.5 touch target */
  border: none; border-radius: var(--r-pill);
  background: var(--grad-1);
  color: #fff;
  font-family: 'Manrope', sans-serif; font-size: 0.88rem; font-weight: 700;
  cursor: pointer;
  transition: transform var(--tr), box-shadow var(--tr);
  box-shadow: 0 2px 14px rgba(155,93,229,0.30);
}
.btn-primary::after {
  content: '';
  position: absolute; top: 0; left: -120%;
  width: 80%; height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255,255,255,0.28), transparent);
  transform: skewX(-15deg);
  transition: left 0.55s ease;
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 22px rgba(155,93,229,0.40); }
.btn-primary:hover::after { left: 160%; }
.btn-primary:active { transform: translateY(0); }

/* ── Ghost & danger buttons ── */
.btn-ghost {
  padding: 8px 18px;
  min-height: 44px;   /* WCAG 2.5.5 touch target */
  border: 1.5px solid var(--border-h); border-radius: var(--r-pill);
  background: transparent;
  font-family: 'Manrope', sans-serif; font-size: 0.82rem; font-weight: 600;
  color: var(--text-2); cursor: pointer;
  transition: all var(--tr);
}
.btn-ghost:hover { border-color: var(--violet); color: var(--violet); }

.btn-danger {
  padding: 6px 14px;
  border: 1.5px solid rgba(241,91,181,0.35); border-radius: var(--r-pill);
  background: rgba(241,91,181,0.06);
  font-family: 'Manrope', sans-serif; font-size: 0.76rem; font-weight: 600;
  color: #c0306a; cursor: pointer;
  transition: all var(--tr);
}
.btn-danger:hover { border-color: var(--pink); background: rgba(241,91,181,0.12); color: #a0204a; }

/* ── Form inputs ── */
.form-input {
  width: 100%;
  padding: 10px 14px;
  border: 1.5px solid var(--border-h); border-radius: 12px;
  background: rgba(255,255,255,0.70);
  font-family: 'Manrope', sans-serif; font-size: 0.88rem; color: var(--text);
  transition: border-color var(--tr), box-shadow var(--tr);
}
.form-input:focus {
  outline: none;
  border-color: var(--violet);
  box-shadow: 0 0 0 3px rgba(155,93,229,0.15);
}

/* ── Badges ── */
.badge {
  display: inline-flex; align-items: center;
  padding: 2px 9px;
  border-radius: var(--r-pill);
  font-size: 0.72rem; font-weight: 700;
}
.badge-violet { background: rgba(155,93,229,0.12); color: var(--violet); }
.badge-cyan   { background: rgba(6,214,224,0.12);  color: #05aab3; }
.badge-green  { background: rgba(6,214,100,0.12);  color: #059950; }
.badge-pink   { background: rgba(241,91,181,0.12); color: #c0306a; }
.badge-amber  { background: rgba(255,179,71,0.15); color: #b06a00; }

/* ── Modal ── */
.modal-overlay {
  position: fixed; inset: 0; z-index: 1000;
  background: rgba(15,23,42,0.48);
  backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
  animation: fadeIn 0.18s ease;
}
.modal {
  background: #fff;
  border-radius: 24px;
  padding: 32px 28px;
  max-width: 520px; width: 100%;
  box-shadow: var(--shadow-h);
  animation: fadeUp 0.22s ease;
}
.modal-title {
  font-family: 'Unbounded', sans-serif;
  font-size: 1.05rem; font-weight: 800;
  margin-bottom: 20px;
}
.modal-footer { display: flex; gap: 10px; justify-content: flex-end; margin-top: 24px; }

/* ── Spinner ── */
.spinner {
  width: 32px; height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--violet);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 30px auto; display: block;
}

/* ── Empty state ── */
.empty {
  text-align: center; padding: 40px 20px;
  color: var(--text-3); font-size: 0.88rem;
}
.empty-icon { font-size: 2.4rem; margin-bottom: 12px; }

/* ── Error text ── */
.error { color: var(--pink); font-size: 0.85rem; padding: 12px 0; }

/* ── Keyframes ── */
@keyframes fadeIn  { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeUp  { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: translateY(0); } }
@keyframes spin    { to { transform: rotate(360deg); } }
@keyframes shimmer {
  0%   { left: -120%; }
  100% { left: 160%; }
}

/* ══════════════════════════════════════════
   SIDEBAR LAYOUT
══════════════════════════════════════════ */
.app-layout {
  display: flex;
  min-height: 100vh;
}

.app-layout > .sidebar {
  width: 230px;
  flex-shrink: 0;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: hidden;          /* sidebar itself does NOT scroll */
  display: flex;
  flex-direction: column;
  background: rgba(238,242,255,0.94);
  backdrop-filter: blur(28px);
  border-right: 1.5px solid var(--border);
  padding: 0 10px 0;
  z-index: 50;
}

.sb-brand {
  display: flex;
  align-items: center;
  padding: 20px 12px 14px;
  margin-bottom: 4px;
}

.sb-logo {
  font-family: 'Unbounded', sans-serif;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
}
.sb-logo span {
  background: var(--grad-1);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.sb-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
  min-height: 0;             /* allows flex child to shrink below content size */
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: none;
}
.sb-nav::-webkit-scrollbar { display: none; }

.sb-link, a.sb-link, button.sb-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  min-height: 44px;   /* WCAG 2.5.5 touch target */
  border-radius: 12px;
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-3);
  transition: all var(--tr);
  cursor: pointer;
  border: none;
  background: transparent;
  width: 100%;
  text-align: left;
  font-family: 'Manrope', sans-serif;
  position: relative;
  white-space: nowrap;
}
.sb-link:hover {
  background: rgba(155,93,229,0.07);
  color: var(--text);
}
.sb-link.active {
  background: rgba(155,93,229,0.10);
  color: var(--violet);
  font-weight: 700;
}
.sb-link.active::before {
  content: '';
  position: absolute;
  left: 0; top: 5px; bottom: 5px;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: var(--grad-1);
}

.sb-icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: inherit;
}
.sb-icon svg {
  width: 18px;
  height: 18px;
  stroke-width: 1.85;
}
/* tab-icon: inline svg в табах и кнопках */
.tab-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}
.tab-icon svg {
  width: 16px;
  height: 16px;
  stroke-width: 2;
}
/* stat-icon: иконки в карточках KPI */
.stat-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.stat-icon svg {
  width: 22px;
  height: 22px;
  stroke-width: 1.75;
}

.sb-divider {
  height: 1px;
  background: var(--border);
  margin: 8px 2px;
}

.sb-badge {
  min-width: 18px;
  height: 18px;
  border-radius: 99px;
  background: var(--pink);
  color: #fff;
  font-size: 0.6rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 4px;
  margin-left: auto;
}

.sb-foot {
  padding: 10px 0 16px;
  border-top: 1px solid var(--border);
  margin-top: 6px;
  flex-shrink: 0;            /* never shrink — always visible at bottom */
}

.sb-user-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 12px;
  transition: background var(--tr);
}
.sb-user-row:hover { background: rgba(155,93,229,0.05); }

.sb-avatar {
  width: 32px; height: 32px;
  border-radius: 10px;
  background: var(--grad-1);
  display: flex; align-items: center; justify-content: center;
  font-family: 'Unbounded', sans-serif;
  font-size: 0.6rem; font-weight: 800; color: #fff;
  flex-shrink: 0;
  overflow: hidden;
}

.sb-user-info { flex: 1; min-width: 0; }
.sb-user-name {
  font-size: 0.78rem; font-weight: 700; color: var(--text);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  margin-bottom: 1px;
}
.sb-logout {
  font-size: 0.68rem; color: var(--text-3);
  background: none; border: none; cursor: pointer; padding: 0;
  font-family: 'Manrope', sans-serif; font-weight: 600;
  transition: color var(--tr);
}
.sb-logout:hover { color: var(--pink); }

.sb-content {
  flex: 1;
  min-width: 0;
  overflow-x: hidden;
}

/* notif wrap — visually separate from nav items */
#notif-wrap {
  border-top: 1.5px solid var(--border);
  margin-top: 6px;
  padding-top: 6px;
}

/* notif drop anchored relative to sidebar */
.notif-drop {
  position: fixed;
  left: 246px;
  width: 320px;
  max-height: 420px;
  overflow-y: auto;
  background: #fff;
  border: 1.5px solid var(--border-h);
  border-radius: 16px;
  box-shadow: 0 12px 48px rgba(15,23,42,0.14);
  z-index: 1000;
  display: none;
  font-size: 0.82rem;
  color: var(--text-2);
}
.notif-drop.open { display: block; }
.notif-drop-header { display: flex; align-items: center; justify-content: space-between; padding: 13px 16px 9px; border-bottom: 1px solid var(--border); }
.notif-drop-title  { font-family: 'Unbounded', sans-serif; font-size: 0.77rem; font-weight: 800; }
.notif-read-all    { background: none; border: none; font-size: 0.72rem; color: var(--violet); cursor: pointer; font-family: 'Manrope', sans-serif; font-weight: 600; padding: 0; }
.notif-read-all:hover { text-decoration: underline; }
.notif-item        { display: flex; gap: 9px; padding: 10px 14px; border-bottom: 1px solid var(--border); cursor: pointer; text-decoration: none; color: inherit; transition: background var(--tr); }
.notif-item:last-child { border-bottom: none; }
.notif-item:hover  { background: rgba(155,93,229,0.04); }
.notif-item.unread { background: rgba(155,93,229,0.06); }
.notif-dot         { width: 7px; height: 7px; border-radius: 50%; background: var(--violet); flex-shrink: 0; margin-top: 5px; }
.notif-dot.read    { background: transparent; border: 1.5px solid var(--border-h); }
.notif-msg         { font-size: 0.79rem; line-height: 1.4; flex: 1; }
.notif-time        { font-size: 0.68rem; color: var(--text-3); margin-top: 2px; }
.notif-empty       { padding: 26px 16px; text-align: center; color: var(--text-3); font-size: 0.83rem; }

/* ══════════════════════════════════════════
   PAGE TRANSITIONS (View Transitions API)
══════════════════════════════════════════ */
@view-transition { navigation: auto; }

/* Shared element: sidebar stays fixed, only main content transitions */
.sb-content { view-transition-name: main-content; }
.sidebar     { view-transition-name: sidebar; }

/* Sidebar: no animation — stays in place */
::view-transition-old(sidebar),
::view-transition-new(sidebar) { animation: none; }

/* Main content: slide + fade */
::view-transition-old(main-content) {
  animation: 180ms cubic-bezier(.4,0,1,1) both vt-slide-out;
}
::view-transition-new(main-content) {
  animation: 260ms cubic-bezier(0,.5,.3,1) both vt-slide-in;
}

/* Fallback for pages without sidebar (login, test-run, test-result) */
::view-transition-old(root) {
  animation: 160ms cubic-bezier(.4,0,1,1) both vt-fade-out;
}
::view-transition-new(root) {
  animation: 240ms cubic-bezier(0,.5,.3,1) both vt-fade-in;
}

@keyframes vt-slide-out {
  from { opacity: 1; transform: translateX(0)  scale(1); }
  to   { opacity: 0; transform: translateX(-16px) scale(.98); }
}
@keyframes vt-slide-in {
  from { opacity: 0; transform: translateX(20px) scale(.98); }
  to   { opacity: 1; transform: translateX(0)  scale(1); }
}
@keyframes vt-fade-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}
@keyframes vt-fade-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ══════════════════════════════════════════
   LOGIN PAGE SPLIT LAYOUT
══════════════════════════════════════════ */
.login-page {
  display: block !important;
  padding: 0 !important;
}
.login-layout {
  display: flex;
  min-height: 100vh;
}

.login-left {
  flex: 1;
  background: linear-gradient(145deg, #0f0c29 0%, #1a1547 40%, #24243e 100%);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  padding: 60px 56px;
}
.login-left::before {
  content: '';
  position: absolute; inset: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,0.055) 1px, transparent 1px);
  background-size: 22px 22px;
  pointer-events: none;
}
.ll-blob1, .ll-blob2 { position: absolute; border-radius: 50%; pointer-events: none; }
.ll-blob1 { width: 520px; height: 520px; background: radial-gradient(circle, rgba(155,93,229,0.32), transparent 70%); top: -160px; right: -100px; }
.ll-blob2 { width: 380px; height: 380px; background: radial-gradient(circle, rgba(6,214,224,0.22), transparent 70%); bottom: -100px; left: 15%; }

.ll-inner { position: relative; z-index: 1; max-width: 440px; }
.ll-logo {
  font-family: 'Unbounded', sans-serif;
  font-size: 1.35rem; font-weight: 800;
  color: #fff;
  margin-bottom: 52px;
}
.ll-logo span {
  background: linear-gradient(135deg, #06D6E0, #9B5DE5);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.ll-headline {
  font-family: 'Unbounded', sans-serif;
  font-size: 1.75rem; font-weight: 800; line-height: 1.3;
  color: #fff;
  margin-bottom: 14px;
  text-shadow: 0 2px 20px rgba(0,0,0,0.25);
}
.ll-tagline {
  font-size: 0.88rem; color: rgba(255,255,255,0.58); font-weight: 500;
  margin-bottom: 40px; line-height: 1.65;
}
.ll-features { display: flex; flex-direction: column; gap: 10px; }
.ll-feat {
  display: flex; align-items: center; gap: 12px;
  font-size: 0.85rem; color: rgba(255,255,255,0.82); font-weight: 600;
  padding: 10px 16px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.09);
  border-radius: 12px;
}
.ll-feat-icon { font-size: 1rem; flex-shrink: 0; }

.login-right {
  width: 450px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 44px 40px;
  background: #f4f6ff;
}
.login-right .auth-wrap {
  width: 100%;
  max-width: 100%;
}

@media (max-width: 840px) {
  .login-layout { flex-direction: column; }
  .login-left { padding: 40px 28px; min-height: 300px; }
  .login-right { width: 100%; padding: 36px 24px; }
  .ll-headline { font-size: 1.35rem; }
}

/* ══════════════════════════════════════════
   A1: STAGGERED ENTRANCE ANIMATION
══════════════════════════════════════════ */
@keyframes cardIn {
  from { opacity: 0; transform: translateY(18px) scale(0.97); }
  to   { opacity: 1; transform: none; }
}
.stagger-item {
  animation: cardIn 0.42s cubic-bezier(0.22, 0.61, 0.36, 1) both;
  animation-delay: calc(var(--i, 0) * 50ms);
}

/* ══════════════════════════════════════════
   D1: SKELETON 2.0 — VIOLET SHIMMER
══════════════════════════════════════════ */
@keyframes ls-shimmer {
  from { background-position: -600px 0; }
  to   { background-position:  600px 0; }
}
.ls-sk {
  background: linear-gradient(
    90deg,
    rgba(155,93,229,0.06) 20%,
    rgba(155,93,229,0.16) 40%,
    rgba(255,255,255,0.7)  50%,
    rgba(155,93,229,0.16) 60%,
    rgba(155,93,229,0.06) 80%
  ) !important;
  background-size: 1200px 100% !important;
  animation: ls-shimmer 1.8s infinite ease-in-out !important;
}

/* ══════════════════════════════════════════
   C2: RICH EMPTY STATES
══════════════════════════════════════════ */
.rich-empty {
  display: flex; flex-direction: column; align-items: center;
  gap: 10px; padding: 52px 24px; text-align: center;
  background: rgba(255,255,255,0.7);
  border: 1.5px dashed rgba(155,93,229,0.22);
  border-radius: 20px;
  backdrop-filter: blur(12px);
  animation: cardIn 0.4s ease both;
}
.rich-empty-svg { opacity: 0.7; }
.rich-empty-title {
  font-family: 'Unbounded', sans-serif;
  font-size: 0.95rem; font-weight: 800; color: var(--text);
  margin-top: 4px;
}
.rich-empty-sub {
  font-size: 0.83rem; color: var(--text-3);
  max-width: 290px; line-height: 1.62; margin-bottom: 2px;
}
.rich-empty-btn {
  padding: 10px 26px;
  background: var(--grad-1); color: #fff;
  border: none; border-radius: 999px;
  font-family: 'Manrope', sans-serif;
  font-size: 0.84rem; font-weight: 700;
  cursor: pointer; transition: all var(--tr);
}
.rich-empty-btn:hover { opacity: 0.88; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(155,93,229,0.3); }

/* ══════════════════════════════════════════
   C1: COLLAPSIBLE SIDEBAR
══════════════════════════════════════════ */
/* Smooth transition for sidebar width */
.app-layout > .sidebar { transition: width 0.28s cubic-bezier(0.4,0,0.2,1); }

/* Label text inside nav links — fades/collapses */
.sb-lbl {
  overflow: hidden;
  max-width: 160px;
  transition: max-width 0.25s ease, opacity 0.18s ease, margin 0.18s ease;
  white-space: nowrap;
  flex-shrink: 1;
  min-width: 0;
}

/* Toggle button (chevron) */
.sb-toggle {
  width: 26px; height: 26px; border-radius: 50%;
  background: rgba(255,255,255,0.85);
  border: 1.5px solid var(--border-h);
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer; flex-shrink: 0;
  box-shadow: 0 1px 6px rgba(15,23,42,0.10);
  transition: background var(--tr), border-color var(--tr), transform 0.28s ease;
  padding: 0; margin-left: auto;
}
.sb-toggle:hover { background: var(--violet); color: #fff; border-color: var(--violet); }
.sb-toggle svg { width: 13px; height: 13px; stroke-width: 2.5; }

/* ── Collapsed state ── */
.app-layout.sb-collapsed > .sidebar { width: 62px; padding: 0 6px 16px; }
.app-layout.sb-collapsed .sb-brand  { padding: 20px 4px 14px; justify-content: center; }
.app-layout.sb-collapsed .sb-logo   { display: none; }
.app-layout.sb-collapsed .sb-lbl    { max-width: 0; opacity: 0; }
.app-layout.sb-collapsed .sb-link   { justify-content: center; padding: 10px 0; gap: 0; }
.app-layout.sb-collapsed .sb-badge  { display: none !important; }
.app-layout.sb-collapsed .sb-user-info { display: none; }
.app-layout.sb-collapsed .sb-user-row  { justify-content: center; padding: 8px 0; }
.app-layout.sb-collapsed .sb-toggle { margin: 0; transform: rotate(180deg); }

/* ══════════════════════════════════════════
   GLOBAL SEARCH MODAL
══════════════════════════════════════════ */
.gs-overlay {
  position: fixed; inset: 0; z-index: 9500;
  background: rgba(15,23,42,0.45); backdrop-filter: blur(12px);
  display: flex; align-items: flex-start; justify-content: center;
  padding: 10vh 20px 20px; opacity: 0; pointer-events: none;
  transition: opacity .18s ease;
}
.gs-overlay.open { opacity: 1; pointer-events: auto; }
.gs-box {
  width: 100%; max-width: 560px; background: #fff;
  border-radius: 20px; box-shadow: 0 40px 100px rgba(15,23,42,0.28);
  overflow: hidden; transform: scale(.96) translateY(-8px);
  transition: transform .18s ease;
}
.gs-overlay.open .gs-box { transform: scale(1) translateY(0); }
.gs-input-wrap {
  display: flex; align-items: center; gap: 10px;
  padding: 16px 20px; border-bottom: 1px solid rgba(15,23,42,0.08);
}
.gs-input-wrap svg { flex-shrink: 0; color: var(--text-3); }
.gs-input {
  flex: 1; border: none; outline: none; font-family: 'Manrope', sans-serif;
  font-size: 0.95rem; font-weight: 500; color: #0F172A; background: transparent;
}
.gs-input::placeholder { color: #B0BEC5; }
.gs-kbd {
  font-size: 0.65rem; font-weight: 700; color: var(--text-3); background: rgba(15,23,42,0.06);
  padding: 3px 7px; border-radius: 5px; line-height: 1;
}
.gs-results {
  max-height: 380px; overflow-y: auto; padding: 8px;
}
.gs-empty {
  text-align: center; padding: 40px 20px; color: var(--text-3); font-size: 0.85rem;
}
.gs-group-label {
  font-size: 0.65rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--text-3); padding: 10px 12px 4px;
}
.gs-item {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 12px; border-radius: 12px; cursor: pointer;
  transition: background .12s;
}
.gs-item:hover, .gs-item.active { background: rgba(155,93,229,0.06); }
.gs-item-icon {
  width: 34px; height: 34px; border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.85rem; flex-shrink: 0;
}
.gs-icon-lesson   { background: rgba(155,93,229,0.1); color: #9B5DE5; }
.gs-icon-course   { background: rgba(6,214,160,0.1);  color: #06D6A0; }
.gs-icon-file     { background: rgba(6,214,224,0.1);  color: #06D6E0; }
.gs-icon-question { background: rgba(245,158,11,0.1); color: #F59E0B; }
.gs-item-body { flex: 1; min-width: 0; }
.gs-item-title {
  font-size: 0.85rem; font-weight: 600; color: #0F172A;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.gs-item-sub {
  font-size: 0.7rem; color: var(--text-3); margin-top: 1px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.gs-item-arrow { color: #ccc; flex-shrink: 0; }

/* ══════════════════════════════════════════
   MOBILE TOPBAR
══════════════════════════════════════════ */
.mob-bar { display: none; }

/* ══════════════════════════════════════════
   RESPONSIVE — TABLET & MOBILE (≤ 768px)
══════════════════════════════════════════ */
@media (max-width: 768px) {
  /* ── Mobile top bar ── */
  .mob-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 56px;
    padding: 0 14px;
    background: rgba(238,242,255,0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 150;
    gap: 10px;
  }
  .mob-bar-logo {
    font-family: 'Unbounded', sans-serif;
    font-size: 0.9rem; font-weight: 800;
    color: var(--text); text-decoration: none;
    flex: 1;
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  }
  .mob-bar-logo span {
    background: var(--grad-1);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
  }
  .mob-bar-actions { display: flex; align-items: center; gap: 6px; flex-shrink: 0; }
  .mob-icon-btn {
    width: 36px; height: 36px;
    border-radius: 10px;
    background: transparent;
    border: 1.5px solid var(--border-h);
    display: flex; align-items: center; justify-content: center;
    cursor: pointer;
    transition: all var(--tr);
    position: relative;
    flex-shrink: 0;
  }
  .mob-icon-btn:hover { background: rgba(155,93,229,0.08); border-color: var(--violet); }
  .mob-icon-btn svg { width: 17px; height: 17px; stroke: var(--text-2); stroke-width: 2; pointer-events: none; }

  /* ── Sidebar becomes fixed drawer ── */
  .app-layout { flex-direction: column; }
  .app-layout > .sidebar {
    position: fixed !important;
    top: 0; left: 0;
    height: 100vh !important;
    width: 272px !important;
    transform: translateX(-100%);
    z-index: 200;
    transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.28s ease !important;
    box-shadow: none !important;
    padding-top: 0 !important;
  }
  .app-layout.sb-open > .sidebar {
    transform: translateX(0) !important;
    box-shadow: 8px 0 40px rgba(15,23,42,0.22) !important;
  }

  /* Backdrop overlay when drawer is open */
  .sb-backdrop {
    display: none;
    position: fixed; inset: 0;
    background: rgba(15,23,42,0.40);
    z-index: 190;
    backdrop-filter: blur(2px);
    animation: fadeIn 0.2s ease;
  }
  .sb-backdrop.open { display: block; }

  /* Hide desktop collapse toggle on mobile */
  .sb-toggle { display: none !important; }

  /* Content: full width, offset for topbar */
  .sb-content { width: 100%; padding-top: 56px; }

  /* Restore labels inside drawer on mobile (ignore collapsed state) */
  .app-layout > .sidebar .sb-lbl { max-width: 160px !important; opacity: 1 !important; }
  .app-layout > .sidebar .sb-logo { display: block !important; }
  .app-layout > .sidebar .sb-link { justify-content: flex-start !important; padding: 9px 12px !important; gap: 10px !important; }
  .app-layout > .sidebar .sb-user-info { display: block !important; }
  .app-layout > .sidebar .sb-user-row { justify-content: flex-start !important; padding: 8px 10px !important; }
  .app-layout > .sidebar .sb-badge { display: inline-flex !important; }
  .app-layout > .sidebar .sb-brand { padding: 20px 12px 14px !important; justify-content: flex-start !important; }

  /* ── Notification dropdown ── */
  .notif-drop {
    position: fixed !important;
    left: auto !important;
    right: 14px !important;
    top: 60px !important;
    width: min(360px, calc(100vw - 28px)) !important;
  }

  /* ── Modal: bottom sheet on mobile ── */
  .modal-overlay {
    align-items: flex-end;
    padding: 0;
  }
  .modal {
    max-width: 100% !important;
    width: 100%;
    border-radius: 22px 22px 0 0;
    padding: 24px 20px calc(32px + env(safe-area-inset-bottom, 0px));
    max-height: 90vh;
    overflow-y: auto;
  }

  /* ── Safe area for fixed bottom elements ── */
  .mob-bar {
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }

  /* ── Login page: handled by login.html inline styles ── */
}

/* ══════════════════════════════════════════
   INLINE SVG ICONS  (.ic)
══════════════════════════════════════════ */
/* Replaces emoji / Unicode symbols throughout the UI */
.ic {
  display: inline-block;
  width: 1em; height: 1em;
  vertical-align: -0.15em;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
  overflow: visible;
}
/* Larger display icons (page headers, empty-state hints) */
.page-header-icon .ic,
.hint-icon .ic,
.complete-icon .ic {
  width: 1.1em; height: 1.1em;
  stroke-width: 1.5;
}

/* ══════════════════════════════════════════
   FEATURE FLAGS
══════════════════════════════════════════ */
/* Student without a class: hide leaderboard */
body.no-class #lb-section { display: none !important; }

/* Gamification kill-switch.
   When admin turns off the feature, body.no-gamification is set by
   api.js/hideDisabledFeatures and EVERY XP / coin / streak / shop /
   achievement / frame element must vanish — across the whole app,
   not just the dashboard. The rules below cover:
     • dashboard widgets (.gam-bar, .lb-widget)
     • profile tabs (achievements, shop, frames)
     • textbook XP badges and progress cards (.hero-xp-badge, .po-xp,
       .xp-bar, .xp-card)
     • a catch-all [data-gamified] hook that wraps any future block —
       authors of new pages should wrap XP UI in a <div data-gamified>
       instead of inventing new classes. */
body.no-gamification .gam-bar,
body.no-gamification .lb-widget,
body.no-gamification .achievements-section,
body.no-gamification #tab-btn-achievements,
body.no-gamification #tab-btn-shop,
body.no-gamification #tab-achievements,
body.no-gamification #tab-shop,
body.no-gamification #frames-section,
body.no-gamification .hero-xp-badge,
body.no-gamification .po-xp,
body.no-gamification .xp-card,
body.no-gamification .xp-bar,
body.no-gamification .xp-pill,
body.no-gamification .xp-badge,
body.no-gamification [data-gamified] { display: none !important; }

/* ══════════════════════════════════════════
   RESPONSIVE — SMALL PHONES (≤ 480px)
══════════════════════════════════════════ */
@media (max-width: 480px) {
  .mob-bar { padding: 0 12px; }
  .modal { padding: 20px 16px 28px; }
  .btn-primary { padding: 10px 20px; }
  .filter-tabs { gap: 4px; }
  .filter-tab  { padding: 6px 12px; font-size: 0.78rem; }
}

/* ══════════════════════════════════════════
   SKELETON SHIMMER
══════════════════════════════════════════ */
@keyframes ls-shimmer-util {
  0%   { background-position: -200% 0; }
  100% { background-position:  200% 0; }
}
.ls-skeleton {
  background: linear-gradient(90deg,
    rgba(15,23,42,0.04) 0%,
    rgba(15,23,42,0.10) 50%,
    rgba(15,23,42,0.04) 100%
  );
  background-size: 200% 100%;
  animation: ls-shimmer-util 1.6s infinite;
  border-radius: var(--r-sm);
}
.ls-skeleton-line { height: 12px; margin: var(--space-2) 0; }
.ls-skeleton-card { aspect-ratio: 1; }
.ls-skeleton-row  { display: flex; align-items: center; gap: var(--space-3); padding: var(--space-3); }

/* ── Utility Classes ── */

/* Visibility */
.hidden    { display: none !important; }
.invisible { visibility: hidden; }

/* Padding */
.p-0 { padding: 0; }
.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-5 { padding: var(--space-5); }
.p-6 { padding: var(--space-6); }

.px-1 { padding-left: var(--space-1); padding-right: var(--space-1); }
.px-2 { padding-left: var(--space-2); padding-right: var(--space-2); }
.px-3 { padding-left: var(--space-3); padding-right: var(--space-3); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }

.py-1 { padding-top: var(--space-1); padding-bottom: var(--space-1); }
.py-2 { padding-top: var(--space-2); padding-bottom: var(--space-2); }
.py-3 { padding-top: var(--space-3); padding-bottom: var(--space-3); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }

/* Margin */
.m-0  { margin: 0; }
.m-1  { margin: var(--space-1); }
.m-2  { margin: var(--space-2); }
.m-3  { margin: var(--space-3); }
.m-4  { margin: var(--space-4); }
.m-5  { margin: var(--space-5); }
.m-6  { margin: var(--space-6); }

.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-5 { margin-top: var(--space-5); }
.mt-6 { margin-top: var(--space-6); }

.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-5 { margin-bottom: var(--space-5); }
.mb-6 { margin-bottom: var(--space-6); }

.ml-1 { margin-left: var(--space-1); }
.ml-2 { margin-left: var(--space-2); }
.ml-3 { margin-left: var(--space-3); }
.ml-4 { margin-left: var(--space-4); }
.ml-5 { margin-left: var(--space-5); }
.ml-6 { margin-left: var(--space-6); }

.mr-1 { margin-right: var(--space-1); }
.mr-2 { margin-right: var(--space-2); }
.mr-3 { margin-right: var(--space-3); }
.mr-4 { margin-right: var(--space-4); }
.mr-5 { margin-right: var(--space-5); }
.mr-6 { margin-right: var(--space-6); }

.mx-1    { margin-left: var(--space-1);  margin-right: var(--space-1); }
.mx-2    { margin-left: var(--space-2);  margin-right: var(--space-2); }
.mx-3    { margin-left: var(--space-3);  margin-right: var(--space-3); }
.mx-4    { margin-left: var(--space-4);  margin-right: var(--space-4); }
.mx-5    { margin-left: var(--space-5);  margin-right: var(--space-5); }
.mx-6    { margin-left: var(--space-6);  margin-right: var(--space-6); }
.mx-auto { margin-left: auto; margin-right: auto; }

.my-1 { margin-top: var(--space-1); margin-bottom: var(--space-1); }
.my-2 { margin-top: var(--space-2); margin-bottom: var(--space-2); }
.my-3 { margin-top: var(--space-3); margin-bottom: var(--space-3); }
.my-4 { margin-top: var(--space-4); margin-bottom: var(--space-4); }
.my-5 { margin-top: var(--space-5); margin-bottom: var(--space-5); }
.my-6 { margin-top: var(--space-6); margin-bottom: var(--space-6); }

/* Gap */
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* Flex / Grid */
.flex          { display: flex; }
.inline-flex   { display: inline-flex; }
.grid          { display: grid; }
.items-center  { align-items: center; }
.items-start   { align-items: flex-start; }
.justify-center  { justify-content: center; }
.justify-between { justify-content: space-between; }
.flex-col  { flex-direction: column; }
.flex-1    { flex: 1; }
.flex-wrap { flex-wrap: wrap; }

/* Text */
.text-xs      { font-size: var(--text-xs); }
.text-sm      { font-size: var(--text-sm); }
.text-base    { font-size: var(--text-base); }
.text-lg      { font-size: var(--text-lg); }
.text-xl      { font-size: var(--text-xl); }
.font-bold    { font-weight: var(--fw-bold); }
.font-semibold{ font-weight: var(--fw-semibold); }
.text-muted   { color: var(--text-3); }
.text-secondary { color: var(--text-2); }
.text-violet  { color: var(--violet); }
.text-success { color: var(--success); }
.text-danger  { color: var(--danger); }
.text-center  { text-align: center; }
.text-right   { text-align: right; }

/* Radius */
.rounded-sm   { border-radius: var(--r-sm); }
.rounded-md   { border-radius: var(--r-md); }
.rounded-lg   { border-radius: var(--r-lg); }
.rounded-full { border-radius: var(--r-pill); }

/* ══════════════════════════════════════════
   ANIMATED BACKGROUNDS (Phase 6)

   Painted by a single fixed div appended to <body> by api.js
   applyCosmetics: <div id="ls-bg-fx" class="bg-<slug>"></div>.
   The container is always position:fixed inset:0 z-index:-1, never
   intercepts pointer events, and sits BEHIND every page chrome.

   Each slug has a static fallback first (no animation), then opts
   into motion outside the prefers-reduced-motion overlay below.
   Picker preview swatches reuse `.bg-preview.<slug>` with the same
   visuals at smaller scale.
══════════════════════════════════════════ */
#ls-bg-fx {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  overflow: hidden;
  will-change: opacity, transform, background-position;
  transition: opacity .4s ease;
}
/* The veil: a translucent white sheet that sits between the animated
   bg layer and page content. Without it, vibrant backgrounds bleed
   straight through every UI element that uses an rgba() fill — chips,
   cards, panel backdrops. With it, the animation reads as a subtle
   accent rather than a takeover. */
#ls-bg-veil {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: rgba(245, 247, 251, 0.78);
  transition: background .4s ease;
}
/* On the 'dark' preset we want a darker veil so light content still
   pops. body[data-bg-tone="dark"] is set by api.js for dark slugs. */
body[data-bg-tone="dark"] #ls-bg-veil {
  background: rgba(15, 23, 42, 0.55);
}
.bg-preview {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  border-radius: 10px;
  overflow: hidden;
  background: #f5f7fb;
}

/* ── 1. none (no overlay) ─────────────────────────────────────── */
.bg-none, .bg-preview.bg-none { background: transparent; }

/* ── 2. gradient-soft (free, static) ──────────────────────────── */
.bg-gradient-soft,
.bg-preview.bg-gradient-soft {
  background: linear-gradient(135deg, #e0e7ff 0%, #fce7f3 100%);
}

/* ── 3. dots (free, static) ───────────────────────────────────── */
.bg-dots,
.bg-preview.bg-dots {
  background-color: #fafbff;
  background-image: radial-gradient(rgba(99,102,241,0.18) 1px, transparent 1px);
  background-size: 22px 22px;
}

/* ── 4. dark (free, static) ───────────────────────────────────── */
.bg-dark,
.bg-preview.bg-dark {
  background: radial-gradient(ellipse at top, #1e1b4b 0%, #0f172a 100%);
}

/* ── 5. gradient-flow (paid, animated) ────────────────────────── */
@keyframes ls-bg-flow {
  0%   { background-position:   0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position:   0% 50%; }
}
.bg-gradient-flow,
.bg-preview.bg-gradient-flow {
  background: linear-gradient(120deg, #9B5DE5, #06D6E0, #FFD166, #9B5DE5);
  background-size: 300% 300%;
  animation: ls-bg-flow 24s ease-in-out infinite;
}

/* ── 6. grid (paid, animated) ─────────────────────────────────── */
@keyframes ls-bg-grid-scan {
  0%   { background-position: 0 0, 0 0; }
  100% { background-position: 0 60px, 60px 0; }
}
.bg-grid,
.bg-preview.bg-grid {
  background-color: #0f172a;
  background-image:
    linear-gradient(rgba(6,214,224,0.18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(6,214,224,0.18) 1px, transparent 1px);
  background-size: 60px 60px;
  animation: ls-bg-grid-scan 18s linear infinite;
}

/* ── 7. bubbles (paid, animated) ──────────────────────────────── */
@keyframes ls-bg-bubble-rise {
  0%   { transform: translateY(0)    scale(0.9); opacity: 0.55; }
  50%  { transform: translateY(-50vh) scale(1.05); opacity: 0.85; }
  100% { transform: translateY(-100vh) scale(0.9); opacity: 0; }
}
.bg-bubbles,
.bg-preview.bg-bubbles {
  background: linear-gradient(180deg, #cbeaff 0%, #e9f5ff 100%);
  position: relative;
}
.bg-bubbles::before,
.bg-bubbles::after,
.bg-preview.bg-bubbles::before,
.bg-preview.bg-bubbles::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 12% 80%, rgba(255,255,255,0.7) 6px, transparent 7px),
    radial-gradient(circle at 38% 90%, rgba(255,255,255,0.5) 9px, transparent 10px),
    radial-gradient(circle at 65% 95%, rgba(255,255,255,0.6) 5px, transparent 6px),
    radial-gradient(circle at 85% 75%, rgba(255,255,255,0.55) 11px, transparent 12px);
  animation: ls-bg-bubble-rise 14s linear infinite;
}
.bg-bubbles::after,
.bg-preview.bg-bubbles::after {
  background-image:
    radial-gradient(circle at 22% 70%, rgba(255,255,255,0.5) 8px, transparent 9px),
    radial-gradient(circle at 50% 88%, rgba(255,255,255,0.6) 4px, transparent 5px),
    radial-gradient(circle at 78% 60%, rgba(255,255,255,0.6) 7px, transparent 8px);
  animation-duration: 19s;
  animation-delay: -6s;
}

/* ── 8. stars (paid, animated) ────────────────────────────────── */
@keyframes ls-bg-stars-twinkle {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.35; }
}
.bg-stars,
.bg-preview.bg-stars {
  background-color: #0a0e27;
  background-image:
    radial-gradient(2px 2px at 20% 30%,  #ffffff, transparent),
    radial-gradient(1px 1px at 40% 70%,  #ffffff, transparent),
    radial-gradient(2px 2px at 60% 20%,  #ffffff, transparent),
    radial-gradient(1px 1px at 80% 50%,  #ffffff, transparent),
    radial-gradient(2px 2px at 90% 85%,  #ffffff, transparent),
    radial-gradient(1px 1px at 10% 90%,  #ffffff, transparent),
    radial-gradient(2px 2px at 50% 10%,  #ffffff, transparent),
    radial-gradient(1px 1px at 30% 50%,  #ffffff, transparent);
  background-size: 200px 200px;
  animation: ls-bg-stars-twinkle 6s ease-in-out infinite;
}

/* ── 9. aurora (premium, animated) ────────────────────────────── */
@keyframes ls-bg-aurora-spin {
  0%   { transform: rotate(0deg)   scale(1.2); }
  50%  { transform: rotate(180deg) scale(1.4); }
  100% { transform: rotate(360deg) scale(1.2); }
}
.bg-aurora,
.bg-preview.bg-aurora {
  background: #050b1a;
  position: relative;
  overflow: hidden;
}
.bg-aurora::before,
.bg-preview.bg-aurora::before {
  content: '';
  position: absolute;
  inset: -40%;
  background: conic-gradient(
    from 0deg at 50% 50%,
    transparent 0%,
    rgba(6,214,224,0.45) 12%,
    rgba(155,93,229,0.55) 24%,
    transparent 36%,
    rgba(6,214,160,0.35) 60%,
    transparent 78%,
    rgba(255,107,53,0.30) 92%,
    transparent 100%
  );
  filter: blur(46px);
  animation: ls-bg-aurora-spin 40s linear infinite;
}

/* ── 10. nebula (premium, animated) ───────────────────────────── */
@keyframes ls-bg-nebula-pan {
  0%   { background-position: 0% 0%, 100% 100%; }
  50%  { background-position: 50% 50%, 50% 50%; }
  100% { background-position: 0% 0%, 100% 100%; }
}
.bg-nebula,
.bg-preview.bg-nebula {
  background:
    radial-gradient(ellipse at 30% 30%, rgba(155,93,229,0.6), transparent 55%),
    radial-gradient(ellipse at 70% 70%, rgba(6,214,224,0.5),  transparent 55%),
    radial-gradient(circle  at 50% 50%, rgba(255,107,53,0.25), transparent 60%),
    #050214;
  background-size: 150% 150%, 150% 150%, 100% 100%, 100% 100%;
  animation: ls-bg-nebula-pan 30s ease-in-out infinite;
}

/* ── Reduced-motion: kill all bg animations, keep static palette ─ */
@media (prefers-reduced-motion: reduce) {
  #ls-bg-fx,
  #ls-bg-fx::before,
  #ls-bg-fx::after,
  .bg-preview,
  .bg-preview::before,
  .bg-preview::after {
    animation: none !important;
  }
}